In a large saucepan, melt butter over medium heat. Add pepper and swirl to toast.
Reduce heat to low. Add pasta and pasta water. Toss to coat.
Toss with Grana Padano.
Remove from heat and toss with Pecorino.
Cook the pasta al dente. It will continue to cook once it has drained, and again when it is added to the butter. No one like soggy spaghetti!This pasta dish is best served as soon as it's made. If you do have leftovers though, store them in an airtight container in the fridge for 2 days. Reheat the pasta gently on the stovetop or in a microwave.Melt the butter on a medium heat so that it doesn't burn. It should melt but not bubble.Cheeses are interchangeable...you can use one or both.I grate the cheeses on the finest side of my grater so that it melts quickly and easily to coat the pasta for that comforting creamy texture. The opposite applies for pepper – I turn the grinder to adjust for larger cracks of the peppercorns for texture and added flavor.